Techno-economic assessment of CO2 bio-fixation using microalgae in connection with three different state-of-the-art power plants

•Systematic investigation of CO2 fixation through microalgae cultivations.•Artificial neural network model to estimate techno-economics of CO2 fixations.•Techno-economic analysis of 3 power plant technologies with CO2 biofixation.•Sensitivity analyis of required microalgae selling prices.•Viability at high photosynthetic efficiencies and at algae prices over $400/t.

Large-scale microalgae cultivations for CO2 bio-sequestration from power plants can be an alternative process to conventional technologies if the capital investments associated with carbon capture, transport and storage can be reduced or avoided. In order to counterbalance the costs required to operate massive microalgae cultivations, it is necessary to create additional revenues through biomass sales. This manuscript examines the techno-economics of microalgae cultivations for the integration with three power plant technologies using an artificial neural network model. The economics are estimated using the net present value approach. The assessment is carried out at photosynthesis efficiencies ranging from 2% to 6%. The sensitivity assessment shows microalgae selling prices in the range of $440–1028/t at a photosynthetic efficiency of 4% for low and high cost scenarios in order to achieve an electricity price similar to that from a conventional power plant without a CO2 capture and storage.